1. Field of the invention
The present invention relates to a droplet ejection device and method using an electrostatic field, and more particularly, to a droplet ejection device and method for generating a specific electric field at a surface of ink adjacent to a nozzle to eject the ink.
2. Description of the Prior Art
A conventional droplet ejection device used in an inkjet printer has a structure that ejects ink using a heater or diaphragm vibration device installed at an inkjet head.
Hereinafter, an example of the inkjet printer using the heater will be briefly described.
First, when current flows through an electrode installed at the heater, heat is generated from the heater, and the heat is sequentially conducted to a protection layer into which the ink is absorbed. When the ink is heated by the conducted heat to generate bubbles, a volume of an upper part of the ink is varied due to the bubbles so that the upper part of the ink is pushed out through an opening formed at a nozzle plate.
As a result, the ink expanded and discharged to the exterior of the nozzle plate is ejected on paper in a droplet shape due to surface tension.
However, such a conventional droplet ejection device has problems of generating a thermal change in the ink due to the heating process for generating bubbles, and degrading print quality due to sudden internal volume variations.